MUSCLE PHYSIOLOGY

Detailed explanation-1: -Thick myofilaments are comprised of around 300 spirally arranged protein molecules called myosin. Each myosin molecule is composed of two heavy chains and four light chains.

Detailed explanation-2: -Introduction. Myosin filaments (also called thick filaments) are key components of muscle and non-muscle cells. In striated muscle, they overlap with thin (actin-containing) filaments in an orderly array, making a repeating pattern of sarcomeres, the basic units of contraction [1] (Figure 1a).

Detailed explanation-3: -Myofilaments are the three protein filaments of myofibrils in muscle cells. The main proteins involved are myosin, actin, and titin.

Detailed explanation-4: -Thin myofilaments Actin is a globular protein with a molecular weight of 43 kDa. Two F-actin strands twisted in a double helix form the backbone of the thin myofilament and possess a complementary binding site for the myosin globular head. Actin has identical isoforms in fast-contracting and slow-contracting fibers.